Tuesday, April 20, 2010
LL Conference Facility (Hilton Clearwater Beach)
Enzymes play vital roles in hydrolyzing lignocellulosic biomass to sugars. Previous studies suggested that the accessibility and reactivity of cellulase and non-cellulase enzymes varied depending on substrates and pretreatment technologies. In this study, cellulases (Spezyme CP, beta-glucosidase, and Accelerase 1000) and non-cellulases (Multifect xylanase and pectinase, beta-xylosidase) were applied to hydrolysis of pure cellulose and xylan. Cellulases and hemicellulases resulted in distinctive sugar release patterns on Avicel, PASC and xylan. Significant amounts of xylooligomers accumulated during xylan hydrolysis with individual cellulases and hemicellulases, suggesting opportunities to optimize the enzyme cocktails. The digestibility of CAFI3 pretreated switchgrass varied with pretreatment technologies (ammonia fiber expansion, aqueous ammonia recycle, dilute sulfuric acid, sulfur dioxide impregnation, and neutral pH/liquid hot water) and were correlative to compositional changes, i.e., xylan, lignin, and acetyl removal. The adsorption capacities of cellulase and non-cellulase enzymes were also measured and correlated with initial hydrolysis rates and the physical and compositional properties of pretreated switchgrass.